FEATURE

Take your positions...

Gemma Church looks at the market for positioning equipment for lasers - where and why it is used, and what benefits it can bring

Positioning equipment is getting complex. Users are now demanding faster, more precise and increasingly accurate kit, with a larger proportion of custom-made pieces being requested to be used within a broader range of applications, and on an increasingly smaller scale.

Positioning equipment comes in many guises – from larger motors and stages strapped to optical tables that work in centimetre ranges, to pieces of apparatus to move beams and photonics kit by hundredths of thousandths of a millimetre. A user really is spoilt for choice when it comes to picking their positioning equipment – so why are more and more companies asking for bespoke pieces of kit when there is so much choice in the marketplace?

There are a number of different players that tend to offer positioning equipment either as a standalone offering or as an appendage to improve a wide selection of products, as Amr Khalil, product line manager at Edmund Optics, explains: ‘As a company that supplies the wider optics market, Edmund Optics has a broad understanding of positioning equipment and how it interacts with optics. Our positioning equipment customers are a combination of those only wanting positioning equipment and those wanting optics with positioning being a value-added product and service.’

Edmund Optics provides a diverse range of positioning products, including: optomechanics offerings such as bench plates, posts and holders, and kinematics; stages that are both manual and motorised with a single or multi-axis; tables and breadboards; and a range of accessories from vibration control to articulating arms and mounting brackets. And Edmund supplies an equally diverse range of customers too, as Khalil says: ‘Our products are geared to serve broad markets. Positioning equipment enables an optical component to do something, but what that something is depends on the demands of the industry and the application.’

OWIS has noticed some more popular positioning applications within its business, as Dirk Schuhen, sales director from OWIS adds: ‘The most popular applications lie within laser material processing (even in industrial applications such as wood processing) and optical inspection (including microscopy and optical sensors) [but] new applications are constantly arising, due to progress within optics and technology.’

OWIS develops, produces and distributes optical beam handling equipment as well as offering a broad range of highly precise positioning systems. These cover stages (linear, XY, elevation, rotation), goniometers and filter wheels equipped with step/DC motors or piezo-drives, together with sophisticated control electronics. Motorised linear stages are also available, which can travel in ranges of up to 1,500mm, but with micrometre precision. ‘OWIS is well represented in photonics markets, such as information technology, sensors, printing, and within biological and medical technologies too,’ according to Schuhen.

And the list of applications for positioning equipment is lengthy, because of the widespread use of lasers, as Thomas Bartholomäus, director of product marketing at Newport Spectra-Physics explains: ‘Lasers are now used as a tool for almost every type of application and, for many of these applications, it is important to move the laser with respect to the workpiece or to move that workpiece with respect to the laser.’

Newport offers a diverse positioning equipment range to a variety of users, as Bartholomäus adds: ‘Newport has four business models for supplying positioning equipment to the market: standard products for researchers, end users and OEM customers; tailored motion systems for unique customer applications, for instance for high-energy laser research or metrology; custom OEM developments of stages and electronics where off-the-shelf products will not do the best job; and dedicated applications for specific technology platforms, for example SolaryX for laser scribing of thin-film photovoltaic panels.’

And when working within systems that incorporate moving parts, a decent set of positioning equipment is required to make sure everything is placed correctly, and moving relative to other equipment at the right pace.

For such moving systems, the industrial photonic applications include laser welding and scribing as well as sensor positioning for online production monitoring. Scientific applications include high precision target and sample movement in a vacuum, non-magnetic or cleanroom environment, as well as microscopy applications, where both the position of a sample and the position of the microscope’s optics need to be controlled.

Piezo-based positioning kit is popular within the market place and is being increasingly used within a range of equipment. Rob Roach, sales manager at Armstrong Optical, explains: ‘Piezo systems tend to be used in optical benches and laser beam control in general, mainly in the linear positioning of optical components, mostly lenses and prisms, and adjusting of the orientation of optical components, mostly mirrors.

‘Other applications for piezo systems include micro assembly of optical components [and], in general, motorised positioners allow remotely controlled adjustments with high resolution and repeatability. This is particularly important for highly sensitive setups or for setups in a closed environment, e.g. a vacuum chamber.’

Armstrong Optical is a distributor for both Feinmess Steinmeyer and Smaract in the UK and offers motorised linear motion options from 12mm up to 0.5m using a variety of drive technologies, such as piezo electric drivers, DC and stepper motors. Other motions include rotation, swivel and lifting. Its core business areas are bespoke OEM motion solutions for traditionally challenging environments, such as within the vacuum, nonmagnetic and clean room applications, as well as where demanding accuracy or repeatability specifications or high degrees of freedom are required.

Tailor-made and tiny

One major trend within the positioning equipment market is an emphasis on increased precision and reliability, but at a reduced cost. In part, this is due to the increasingly demanding and diverse applications the kit is being used within and in part reflected by what is going on in the wider photonics arena. Chris Iaconis, product line manager of electro optics and motion control from Bookham, says: ‘Applications are increasing in precision and complexity, requiring motion control and optomechanics products with better resolution and improved stability.’

Bookham develops and manufactures a broad range of both manual optomechanics and automated motion control components and subsystems for controlling the position of photonics elements and controlling the pointing and position of laser beams. It markets its optomechanics and motion control products under the New Focus brand. The company also offers a variety of standard kinematic mounts and stages as well as custom mounting solutions. Many of its products incorporate its patented Picomotor actuator, which enables automated motion control at the 30nm level or better. In addition, it offers a line of Position Sensitive Detectors (PSDs) for measuring the X-Y position of a laser beam.

The M-810, which is an electro-mechanical, high-force Hexapod 6-axis micropositioning system from Physik Instrumente.

This move towards an increasingly precise set of kit has also been seen by Edmund Optics’ Khalil, who says: ‘Positioning equipment is not a revolutionary market. However, there have been many subtle changes over the years in materials, resolution and automation. Users are demanding increasingly accurate equipment with greater degrees of freedom and better final movement measurement.’

And Newport’s Bartholomäus sees the positioning equipment market placed under pressure to reduce costs, as he adds: ‘Positioning equipment is not a market by itself, as it is a supporting technology, but we do see a number of trends developing. For example, the marketplace is demanding higher throughput systems with a better economy, which directly affects the positioning market. This is particularly true for the microelectronics industry, which is under tremendous cost pressures.’

And microelectronics is a major application area for precise positioning equipment, as Bartholomäus says: ‘There are many areas where precision positioning equipment is used in combination with lasers, but the microelectronics market is one of the most demanding and largest. Here positioning equipment is used for a range of applications, including lithography, wafer inspection, trimming and repair or singulation.’

‘Within microelectronics, positioning equipment is a key component as the process needs to be so accurate, reliable and fast. Process repeatability with single-digit to sub-micron precision is a key requirement for most of these applications,’ he adds.

Armstrong’s Roach also notes a move to speedier systems: ‘In general there is a push for higher accuracy, precision and repeatability. The industrial sector is always pushing on speed as well, whereas the more scientific applications are also concerned with mechanical stability.’

Physik Instrumente (PI) is also seeing a push towards improving precision, as Kevin Grimley, managing director at PI, explains: ‘Positioning equipment is used extensively in the photonics industry. For us sample and beam alignment applications are most common. The push towards higher and higher imaging resolution has led to a demand for more precise beam and sample positioning.’

‘In the biophotonics market, work on live cell imaging has helped drive forward requirements for faster beam and sample alignment products. PI has focused on providing a wide range of nanopositioning stage options for this market, investing in technologies to enhance the resolution, repeatability, speed and off axis precision of our products,’ says Grimley.

PI supplies a range of positioning kit, including piezo-based nanopositioning systems, with an extensive range of low and high voltage piezo actuators, piezo driven stages and piezo electronics. It also provides ultrasonic and stepping piezo motor technologies and a comprehensive range of motorised micropositioning stages, including sixaxis hexapods. Grimley adds: ‘Our products are used by both photonic-based product manufacturers and R&D labs in a diverse range of applications.’

Size zero and custom-made

As users demand increasingly accurate and precise pieces of positioning kit, there is, in turn, an increased need for more bespoke pieces of kit too. PI’s Grimley says: ‘In the past a number of customers got by, by building their own positioning stages using off the shelf components. As the demand for precision and speed has increased and the time to market has reduced, more and more customers have decided to turn towards specialist suppliers that have the experience and product range available to provide a quality solution quickly.’

‘Selecting the right positioning system usually means combining the right drive, mechanics and sensor with an appropriate controller, interface and software solution. This is best done by detailed consultation with a knowledgeable supplier. Within PI we have found that most industrial applications require some level of customisation and so we have organised our manufacturing and R&D group to be able to deal rapidly with such requests,’ Grimley adds.

A move to miniaturisation is also driving demand for custom-made pieces of positioning equipment, rather than out-of-the-box offerings, as OWIS’ Schuhen says: ‘The positioning equipment market is a very vital and fast-growing one. Offering customised solutions is increasingly important. Demand for a great variety of even smaller higher precision customised systems also take advantage of new drive principles, e.g. piezo-drives, mini-motors with micro-gears.’

Armstrong’s Roach says: ‘We see the positioning equipment market moving towards smaller and more complex, precise, bespoke systems. Piezobased positioning systems are leading this trend since they combine high miniaturisation, high resolution, large velocity ranges and backlash-free motion without gears therefore supporting the miniaturisation of the laser and other auxiliary equipment.’

Nanophotonics – the study of light on the nanoscale – is also creating demands to make positioning equipment even smaller and more precise, as Bartholomäus says: ‘An emerging market with very demanding requirements to the positioning equipment is within nanophotonics. Here, features down to a size of 100nm may need to be inscribed and therefore the motion equipment used needs to be very accurate and the lasers need to be highly stable, too. Most of these processes also require precise synchronisation between the laser and the position of the motion system.’

‘Although nanophotonics is really a research application at the moment, it could have more commercial applications in the future,’ he adds.

OWIS is targeting the nano-sized arena too, as Schuhen adds: ‘OWIS extended its offerings to piezo-driven nanopositioning systems to close the gap between step/DC motor stages with millimetre travel and micrometre precision and piezo-actuators with micrometre travel and nanometre precision. Piezo-drives offer several millimetres of travel together with an accuracy of better than 100nm.’

Nanophotonics isn’t the only technology to affect the positioning equipment market though, as Grimley explains: ‘New technologies based on ultrasonic and stepper piezo motor drives have come onto the market in the last few years. These technologies allow the build of extremely compact stages with some unique properties. Ultrasonic piezo motors offer speeds of several 100mm/s, while maintaining sub-micron precision, and piezo step drive motors offer millimetres of travel while maintaining sub-nanometre resolution. Both technologies can be modified for use in a vacuum or for use in applications where magnetic fields create an issue.’

And the move to piezo positioning equipment is being driven by more demanding environments, as Grimley adds: ‘Piezo motor driven stages will replace other technologies in some applications and will allow the use of positioning in some environments where previously there has been no solution available.’

Competitive times

The future is looking bright for the positioning equipment market, with Armstrong’s Roach describing the current state of the market as ‘very buoyant’.

The only potential threat to the market comes from low-cost suppliers, but the high-quality products should weed out the lower-quality kit, as Khalil says: ‘The only possible threat is low-cost manufacturers, which might cause some price cost erosions. However, there will always be demand for higher quality products, which tend to be less affected by price erosions.’

And the current state of the economic market has not helped matters, as Grimley adds: ‘The positioning equipment market has been growing rapidly in recent years, and so has the number of suppliers trying to gain a share of the business. With the global economy going through an uncertain time, however, it may be that some suppliers will face real hardship. But the underlying requirement for higher and higher precision and faster and faster alignment will remain and the market will continue to grow significantly in years to come.’

There is an air of optimism for the future of the positioning equipment market, because the technology is so ingrained within the wider photonics arena, as Bartholomäus says: ‘For most photonics applications, a user must have positioning equipment or how else would they do their job?’

Bartholomäus adds: ‘I do not see anything threatening the positioning equipment market over the next few years – in fact I predict the reverse. The positioning equipment market will increase in importance as the trend for automation within the photonics industry develops.’

So manufacturers and users can breathe easy for the next few years, as Khalil sums up the general mood felt within the positioning equipment market and adds: ‘The need for the product exists and that will not change in the immediate future.’